Method and apparatus for coating sheet materials



TM WM.. y H. A. SHEESLIEY 2,251,295

METHOD AND APPARATUS FOR coATING SHEET MATERIALS Filed Nov. 2, 1936 3Sheets-Sheet 1 NVENTR ATTO RN EY Aug E'H1941- H. A. SHEESLEY M935 METHODAND APPARATUS FOR COATING SHEET MATERIALS Filed NOV. 2, 1936 3Sheets-Sheet 3 lNVENTOR Horam (Www/@W BYMW JKM@ ATTORNEY Patented Aug.5, 1941 METHOD AND APPARATUS Fon ooATING snEET MATERIALS Horace A.Sheesley, Portlandyltlaine, assls'ncr to Tuiide Products Corporation,Portland, Maine, a corporation of Maine Application November 2, 1936,Serial No. 108,789

Claims.

This invention relates to an vimproved method and apparatus for coatingsheet materials, and more particularly to a method and apparatus forapplying a uniform coating compound to sheet materials such as paper,paperboard, textiles, and the like, and also to an improved waterproofand greaseproof paper and paperboard which can be economically andexpeditiously manufactured by my improved method and apparatus.

Paper and paperboard material have heretofore been treated with acoating of wax, parafiin or asphalt to make the same resistant tomoisture. Wax and paraffin is expensive material, and to a certainextent difficult to vapply due to the heating and cooling treatmentrequired. Asphalt is also diilcult and expensive to apply, requiringexpensive machinery and equipment. A further serious drawback of Wax andparaiiin and asphalt coatings is that they are affected by heat andtemperature changes. Wax melts at approximately 130 F. and at this`temperature will flow off and lose its waterproofing qualities. Both.wax,.paraln and asphalt soften to much lower temperature, rendering thesurface sticky and tacky and generally undesirable for commercialpurposes.

A coating resistant to the passage of grease and oil therethrough haslong been sought for. Wax. parailin and asphalt coated papers are onlypartially resistant lto the passage of grease and oil therethrough andare not satisfactory, since they soften under moderately warmatmospheres rendering the same greasy, sticky and porous.

It is an object of my invention to provide an improved paper andpaperboard material suitably treated so as to make the same waterproof,I

greaseproof and oilproof.

`.Another object of my invention is to provide a waterproof andgreaseproof paper and paperboard which can be manufactured at low cost,quickly and expeditiously, which has greater strength and flexibilitythan treated papers heretofore provided, which will not crack ordeteriorate by flexure or rough handling, which is odorless and does notdeleteriousltr effect foods and other products packed therein, which isfurthermore not affected by heat or temperature changes and which is afire and combustion retardent.

Another object of this invention is to provide an improved coatingcomposition which is substantially waterproof and greaseproof.

Still another object of this invention is to provide an improved methodand improved apparatus for coating paper, paperboard, Paper stock of allkinds and other sheet materials which can be carried out expeditiouslyand economically and by which a high quality coated material can beproduced.

Another object of this invention is to provide an improved `apparatusfor manufacturing coated papers, paperboard, paper stock and other sheetmaterials which is low in cost as compared with apparatus heretoforeused for such purposes, which can be operated with a minimum ofattention and largely by unskilled labor, which is durable and lastingin construction, and which permits manufacture of coated paper andpaperboard. and other coated sheet materials so as to produce a highlysatisfactory and desirable product efficiently, expeditiously and at lowcost.

Other objects of this invention will become apparent as the disclosureproceeds.

In accordance with this invention, the paper, paperboard or other sheetmaterial to be coated is supplied in suitable rolls or in sheets. Myimproved coating composition is applied to the rolls or sheets by spraymechanism which applies a homogeneous and uniform coating on the sheetmaterial as it moves continuously under the spray mechanism. Immediatelyafter the.

application of the coating, the surface is subjected to a pressing andspreading action which forces still further the coating composition intothe outer fibres of the sheet and spreads the coating in a smooth, evenand homogeneous layer 'thereoven The coated web is thereafter runthrough a suitable drying chamber which operates to hasten the escape ofthe evaporable components of the coating solution and also hastens thesolidication or hardening of the coating material upon the moving web.

It will be noted 'that the coating is applied while the stock is in dryor substantially dry condition and thus the web can Vbe easily andefficiently handled. 'Ihe coating composition comprises a latex4solution which may be combined with a fat-free animal glue. such as fishglue, animal glue or gelatin. The ordinary vegetable glues such as thosemade from stanches now available commercially have not provensatisfactory. A suitable preserving agent, such as formaldehyde, isadded to the mixture and a congeallng agent, such as an alcohol, isapplied to the mixture whichserves to congeal the same when spread overthe sheet or web material.

Various other features and advantages of the invention will be apparentfrom the following advantages, and the manner in which it may be carriedoutmmay be better understood by referring to th following descriptiontaken in connection with the accompanying drawings forming a partthereof, in which:

Fig. 1 is a top plan view of my'improved ap paratus for making thewaterproofed paper and paperboard by the method herein described, cer,-tain parts being broken away to `expose the interior; i

Fig. 2 is a side elevational view of the complete apparatus, theapparatus-enclosing housing being broken away to expose the same toview;

Fig. 3 is an enlarged front elevational view of the apparatus showingparticularly the coating applicator operating in conjunction `with thespreader knife to apply a uniform layer of the coating material to thepaper surface;

Fig. `4 is an enlarged fragmentary diagrammatic view showing thearrangement of the spreader knife, the coating applicator, and ifdesiredan applicator by which a suitable hardeningl accelerator may beseparately applied;

Fig. 5 is a vertical longitudinal cross-sectional view of a coatingapparatus designed to apply coating to both surfaces of the web; and

Fig. 6 is a magnified cross-sectional view showing a section of paperor'paperboard having my improved Waterproof greaseproof coating appliedto both surfaces thereof. A

Similar reference characters refer to simila parts throughout theseveral views of the drawings and specification.

I have found that a mixture of rubber latex and fat-free glue providesan excellent coating material for the paper or paperboard. Asillustrative of the general mixture used, a satisfactory coatingcomposition has been made from a solution comprising approximately 50%to 60% of commercial latex containing approximately 40% rubber solidsmixed with-approximately 40% to of liquid glue comprising approximatelysix pounds ,of water to one pound of fat-free glue solids. To this maybe added a preservative, such as formaldehyde, and to retain the latexin a wo'rkable condition, standard ammonia may be added. The latexgenerally contains some ammonia and the amount to be added depends to agreat extent on the speed at which coagulation of the latex is to beeffected. Coagulation of the latex and the glue is effected by theapplication of alcohol to the latex glue solution, which is preferablyapplied during or immediately after the application of the latex gluemixture to the paper so as to prevent the possibility of any substantialcoagulating action prior to the actual contact Vof the latex gluemixture to the paper surface. I have found that a coagulating materialwhlc contains a major percentage of alcohol, and

known commercially as Shellacol, has proven to be an excellentcoagulating medium. To two gallons of the latex glue mixture comprisingapproximately of latex having approximately 40% solid rubber content,and approximately 45% liquid glue is added approximately one-half ounceof formaldehyde, approximately 4 ounces of alcohol or Shellacol, and asuicient amount of standard ammonia to keep the material workable untilthe coating has been applied. It is under- "stood that the proportionsabove given are illus- 4the paper or paperboard web as the web movesunder the spray nozzles. The spray nozzles should be so arranged as toapply a uniform coatlng to the paper surface and to fully coat the same.'I'he coated paper surface then immediately comes into contact with thespreader blade which serves to even out any irregularities and give thenished material a smooth and even texture, filling in any uncoated areasof the paper surface. 'I'he spreader blade also assists in forcing thecoating mixture into the surface so that a firm bond between the coatingand the paper is produced. It has been found that the alcohol orcoagulating agent maybe added to the latex glue mixture at the nozzleswhere it is immediately ejected onto the paper surface with the latexglue mixture before it vhas an opportunity to coagulate the same. If thecoagulating medium and the latex mixture are to be appliedsimultaneously the apparatus should be so constructed as to permitimmediate ejection of both materials beforeV any marked coagulatingaction can take effect.

The coagulating agent may also be separately applied by spray nozzles asthe web leaves the spreader blade. The coated web is then run through adrying tunnel which may be suitably heated to expedite the escape of thefugitive cornponents of the coating mixture, after which the paper orApaperboard may be' cut into sheets or wound upon the roll. It is alsounderstood that my `process contemplates coating both sides of the paperor paperboard surface, if desired.

Under ordinary circumstances, it is known that late x and rubbercompositions as generally manufactured deteriorate rapidly, and that ina few months time the solidified latex loses a great deal of itselasticity and toughness. I have found, however, that when latex iscombined with the alcohol and formaldehyde in the above proportions,that a preserving action is effected which produces a coating which isstrong, resilient, tough and durable, and is both waterproof andgreaseproof. Nofdeteriorating effects are noted many months aftermanufacture. f The apparatus for carrying out my improved processmaycomprise a spray apparatus A and a web-supporting, web-coating andweb-drying machine B. The operating elements of the coating machine, asshown more particularly in l'igs, 1, 2 and 3 of the drawings, maycomprise a supporting table including a horizontal frame I supported onthe spaced legs 2, 3, 4 and 5. Suitable reinforcing struts 6 and 1 maybe provided to stiffen and strengthen the table. Much of the operatingapparatus is positioned at the head end of the table and if preferable,therefore, the legs 2 and 3 may be relatively closely spaced to supportthe weight thereof. A roll of the selected paper or paperboard P issupported by a shaft I0. The shaft I0 is rotatably mounted in suitablebearings I2 provided in each of a pair of brackets II supported by thetable legs 2. The paper web P passes over a roller I3 having a resilientrubber surface. The roller I3 is xed to a shaft I4 which is rotatablymounted in bearings 2| provided in the supporting standards I standingon the table frame I. The coating material is applied to the surface ofthe paper P as it passes over the roller I3. To maintain the paper webin a fixed plane as the coating mixture is applied, it is preferable toprovide a guide roller I I3 which is positioned between the paper roll Pand the cylinder I3.

The'coating material is preferably applied to the surface of the paper Punder pressure of from to 50 pounds per square inch. The apparatus forapplying the coating solution is shown more particularly in Figs. 2 and3 and may comprise generally a coating solution supply line 80 intowhich the coating solution is conducted through the conduit 8| from asuitable source of supply. The coating solution flows into the severalbranch conduits l82 each supplying a spray nozzle 83. Air pressure isused to expel the coating solution from the nozzles 83 in the form of adrenching mist, air under pressure from a suitable source of supplyflowing into the air supply line 84. The air supply line 84 also has aplurality of branch conduits 85 extending therefrom, each branch conduitsupplying its respective nozzle 83 with the desired air pressure whichoperates to expel the coating solution with the proper force.

formly coat the paper surface with the required amount of coatingmaterial applied to the proper thickness and density.

Further means, including a spreader knife 22, is provided which operatesto spread the coating solution onto the paper surface in a smoothuniform layer which will produce a coating sufficiently dense anduniform to fully protect the paper web P from contact with `moisture orgrease which may be applied to the coated Isurface. The spreader knife22 comprises more particularly a heavy steel plate having thel bottomsurface 23 thereof shaped to accurately conform to the cylindricalsurface of the roller I3. The spreader knife 22 is vertically adjustablein suitable guides provided on the standards I5. More particularly,vertical adjustment of the spreader knife 22 may be accomplished bymeans of suitable adjusting devices comprising a clamp element 24, fixedto each end of the spreader knife 22, each clamp 24 being secured in asuitable slide block 25 adapted to vertically slide within a guideopening 26 provided in each of the standards I5. An adjusting screw 28,provided with a hand wheel 29 to manipulate the same, extends throughsuitable threaded openings in the sliding block 25. By manipulating thehand wheels 29 at each end of the spreader knife 22, it is seen that thespreader knife may be raised and lowered as desired to present the lowerspreading edge 23 thereof in the -desired spaced position with respectto the paper web -P passing over the roll I3. Thus the thickness of thecoating applied to the web P may be regulated. The spreader knife 22 and-associated guide block 25 may be removed from the standard I5 forrepair or replacement by removing the guide plate 21 from its associatedblock 25, which guide plates retain the blocks 25 in fixed slidingposition within the standards I5.

Preferably immediately following the spreading of the coating solutionby means of the spreader knife 22, an additional solution which fstandards 89.

will hereafter be called an accelerator, is preferably applied to thecoated surface. The accelerator Imaterial contains constituents whichwill accelerate the hardening of the coating constituents and furtherassist in the escape of the fugitive components of the coating solution.The

applicator for applying the accelerator solution may be similar to thatused in applying the coating solution, comprising an acceleratorsolution supply conduit a which receives the solution from a suitablesource and conducts it into the branch conduits 82a. eachof whichsupplies the accelerator solution nozzles 83a suitably supported upon abar -8'Ia extending horizontally across the moving web of coated paperP. Air under pressure from a supply conduit 84a passes into the branchconduits a and acts to force out the accelerator solution through thenozzles 83a under pressure. A sufficient number of nozzles 83a areprovided to apply the desired quantity of accelerator solution to thecoated Web. The nozzle-supporting bar |Illa is in turn supported bysuitable uprights 88a having vertical telescoping adjustment with thesupporting The accelerator` solution, upon striking the coatingsolution, operates to congeal and hardemftlle same and facilitate theescape of the fugitive or liquid components thereof.

It has been found that the accelerator solution under pressure may besupplieddirectly to the nozzles 83a which spray the coating materialonto the web. 4The entry of the accelerator solution into the nozzles83a should be so arranged so that the accelerator solution is not givenan vopportunity to congeal or harden the coating solution before itstrikes vthe paper web.

As soon as the accelerator solution has been applied to the web, the webpasses int a suitable drying tunnel |00 in which the coating applied tothe web is hardened and dried. The drying tunnel I IIIJhouses andencloses a considerable portion of the web-supporting table. A heatedweb-supporting roll 4I is fixed to a suitable shaft 42, the ends of theshaft being rotatably mounted in suitable bearings 43 carried bysupporting brackets 44 resting on the table frame I. The roll 4I isdriven in synchronism with the roll I3 by operating mechanism which willhereinafter be described; The coated web P2 in the process of drying isreturned to the front end of the apparatus where it passes around aheated guide roll 45 fixed to a suitable shaft 46 rotatably mounted inbearings 4I suitably supported from the table frame I. If desired, theguide roll 45 may be positioned outside of the tunnel housing |00 so asto permit inspection of the coating to determine the progress of thedrying action. 'The coated web P2 returns into the tunnel drier |00 andpasses around a heated guide roller 5|] at the foot end of the tunnel.The guide roller 5D may be supported on a suitable shaft 5I rotatablymounted in suitable bearings 52 supported by brackets 53 fixed to thesupporting legs 5 of the table. If further drying action of the web P2is desired, the web may be again run through the drying tunnel to thefront end thereof and passed around another heated guide roller 55 fixedto a suitable shaft 56 rotatably mounted in bearing 51 carried bysuitable brackets 58 xed to table-supporting legs 3. The web P2 returnsto the foot end o f the tunnel and passes out of same through a suitableopening 6E, at which point the coating on the web is dry and thecoatedweb may be wound upon a suitable roll or cut into strips. It will benoted that either one or both of the rolls 45 and 55 may be mountedinside or outside of the drying tunnel |00, as desired, and likewise theguide`rolls 4I and 50 may be mounted either inside or outside of thedrying tunnel |00. A suitable heating medium, such as steam, isconducted into each of the rolls 4|, 45, 50 and 55 through a suitablesupply conduit 42a connected to the hollow shaft which supports therolls.

Suitable driving means are provided for driving the spreader roll I3 andthe various guide rolls 4I, 45, 50 and 55 in synchronism so that noundue stresses will be placed upon the web as it passes around theserolls. The driving force, such as a belt driven by a suitable motor, istrained around the stepped pulley wheel I8, Which permits adjustment ofthe belt so that the apparatus can be run at any selected speed. Pulleywheel 8 is xed to a suitable shaft I9 rotatably mounted in suitablebearings 20 supported by the table frame. A train of gears, comprisingthe gear I6 fixed to the shaft I9 which meshes with gear II fixed to oneend of, the shaft |4 of the roll I3, operatively connects the roll I3with the drive pulley I8.

The va'rious guide rolls 4|, 45, 50 and 55 may be operatively connectedto one end of the shaft I4 of the roll I3. Mo-re particularly, a bevelgear 3| fixed to one end of the sha/ft I4, meshes with a bevel gear 32fixed to a longitudinally extending shaft 33 which operates to driveytpe/guide roll 4I at the foot end of the apparatus.` ,/The shaft 33 maybe rotatably mounted in suitable bearings 38 provided in the spacedbrackets 34, 35, 36 and 31 fixed to the table frame I. A bevel gear 39at the foot end of the longitudinal shaft 33 meshes with bevel gear 44fixed to the shaft 42 supporting the guide roll 4|. The drive connectionbetween the spreader roll |3 and the guide roll 4I is such that theperipheral speed of rotation of the guide roll 4I is the same as that ofthe spreader roll I3.

The guide roll 50 may be driven by means of a suitable drive connectingthe shaft 42 of the roll 4I and the shaft 5| of the roll 50. This driveconnection may comprise a sprocket gear 59 fixed to the shaft 42 ofguide roll 4I over which is trained a drive chain 60 which is alsotrained over the sprocket wheel 6I fixed to the shaft 5| of the roll 50.

Guide roll 45 may be directly connected to the shaft I4 of the spreaderroll I3 by means of suitable driving mechanism comprising a sprocketgear 62 connected to the shaft I4, a sprocket gear 64 attached to theshaft 46 of guide roll 45, the

sprocket wheels 62 and 64 being connected by a suitable drive chain 63.

Likewise,A guide roll 50 may be operatively connected to guide roll 45by means of a sprocket wheel 65 attached to the shaft 46 of guide roll45. A sprocket wheel |66 is attached to the shaft 56 of the guide roll55 and nally a suitable drive chain 61 is operatively connected to thesprocket wheels 65 and 66.

The drive connection between the spreader roll I3 and the guide rolls 4Iand 50, 45 and 55, is so arranged and adjusted that the peripheral speedof the spreader roll I3 and the various guide rolls is maintainedsubstantially uniform, so as to obviate the possibility of any pullingstresses being exerted on the web passing around the same. It will benoted that separate drive means may be provided for one or all of theguide rolls 4|, 50, 45 and 55, if desired, although it is generallypreferable to drive al1 the guide rolls as well as the spreader roll I3from the same source of power so as to obviate the possibility ofpulling stresses on the web which might otherwise deve op.

Suitable drying means are preferably provided within the drying tunnelto hasten and facilitate the drying of the coated web. The drying meansmay comprise a suitable arrangement of steam or hot water heated coils,an electrical heating device, or other suitable heating means. I haveshown and illustrated in Figs. 1 and 2 a heating device which compriilsa plurality of parallel arranged pipes '|0 suitably connected by elbows'|I to provide a continuous conduit of serpentine form. The inlet end 12may be connected to a suitable steam or hot water supply. The cooledsteam or Water may be withdrawn from the outlet 13. The steam or hotWater coils may be supported in suitable frames I4 suspended from thetable frame I. While only one row of heating coils is shown in Figs. 1and 2 itis understood that two or more rows of heating coils may beprovided positioned between adjacent moving webs. The coils are designedto maintain the temperature of the tunnel at from 180 to 350 F. Asuitable outlet IOI is provided in the tunnel to permit the escape ofthe evaporable constituents of the coating. It is understood that thetunnel |00 may be of any length necessary to effect the desired dryingaction of the coating.

There is illustrated more or less diagrammatically in Fig. 5a somewhatmodified apparatus adapted to coat both sides of the paper web P. In thearrangement here shown the paper or paperboard P to be coated is reeledol the roll supported on the shaft I0, which rotates in a suitablebearing I2 carried by a suitable supporting `bracket I I a. The movingweb P passes under the coating solution spray nozzles 83 which appliesthe coating to one surface of the paper web. The web then passes underthe spreader knife 22 and thereafter passes under the acceleratingsolution spray nozzles 83a, and then into the drying tunnel |00 where itpasses around the guide rolls 4|, 45, 50 and 55 and 90. 'Ihe apparatusso far described may be similar to the apparatus shown and illustratedin Figs. 1, 2 and 3 and heretofore described. When completely orpartially dried the coated web P2 passes out of the tunnel |00 through asuitable exit opening |05 and thereafter passes over a second spreaderroll I3a which is similar in construction to the spreader roll I3 abovedescribed. It will be noted that the uncoated surface of the web P2 isuppermost as it passes over the spreader roll |3a. A second coatingsolution spray nozzle 83 constructed similar to the spray nozzleheretofore described, applies the coating solution to the uncoated faceof the web before it passes under the spreader knife 22a, as the webmoves toward the left as shown in Fig. 5. The spreader knife 22a may bemounted and constructed similar to the spreader knife 22 heretoforedescribed, and operates to spread thev coating uniformly over thesurface of the web. A series of accelerator solution spray nozzles 83aare positioned on the opposite side of the spreader knife 22a andoperate to apply the solution to hasten the solidification of thecoating solution. The web, coated on both sides, then passes around therotatably mounted guide roll I06 .and then passes through the inletopening |06' in the tunnel drier |00 where the coating last applied isdried and nally hardened. The coated web P4 passes around the drivenguide rolls 4 Ia, 45a, 50a,

55a, and over the finalv guide roll 90a, at which point it passes out oftunnel drier through the outlet opening |01 and is Wound upon aysuitable reel |00. The guide rolls 4|, 45, 50, 55 and 90 and also theguide rolls 4|a, 45a, 50a, 55a, and 90a may be operatively connected toand drive in synchronism with the spreader roll I3 in the mannerheretofore described and may also be heated as above described. Theapparatus herein described is adapted to coat both sides of the paperweb and solidify the coating C so that the coating becomes homogeneouslybonded to both surfaces of the paper web P, providing a coated paper P4both sides of which is moisture and grease resistant.

In carrying out the process it is preferable to apply the coatingsolution immediately in advance of the spreader knife 22 sothat thecoating is not given the opportunity to solidify to any appreciableextent before it is acted upon by the spreader knife 22a. Theaccelerating solution applied by the spray nozzles 83a is preferablyapplied immediately following the passage of the coated paper web fromunder the spreader knife 22a so as to effect an initial congealing andhardening of the coating before it passes into the drying tunn l |00.While the above arrangement is prefer ble it is understood, however,that the accelerating solution may also be applied-immediately prior tothe passage of the coated web into contact with the spreader knife 22and spreader knife 22a. The drying tunnel is of sufcient length toeffect the case-hardening of the coating so as to remove any stickinessor tackiness therefrom as it passes around the guide rolls 45 and 55,where the coated surface of the paper web contacts these rolls. Where itwould be inconvenient to provide a tunnel of sufiicient length to eiectthis result it is understood that the coated web could be given a halftwist so that the uncoated side of the paper web only would contact thefront end guide rollers 45 and 55.

My improved method and apparatus is agapted not only for coating paperand paper oard material with any desired compound, such as that abovedescribed, but can also be advantageously used to coat other sheetmaterials, such as cloth, textiles and fabrics. It is, therefore,understood that where the words paper or paper web are mentioned inconnection with the method and apparatus herein described and claimed,other webs of various sheet materials are also intended to be coveredthereby. For example, waterproof and greaseproof cloth and textiles suchas used in making raincoats, tarpaulin, oilcloth, linoleum, and likeproducts, can also be manufactured by my improved method and apparatusherein described and claimed.

The invention embodied in this application is also directed to animproved waterproof and/or greaseprocf paper and paperboard, which iswell adapted for the manufacture of various commodities, such as paperbags, paper cement sacks, waterproof and/or grease proof wrappingpapers, paperboard containers, cartons and boxes, for the shipment andstorage of numerous productsI of commerce, either granular, liquid orsemiliquid in nature, and other products which require a Waterproofand/or greaseproof container or wrapper. f

While 'certain novel features of the invention have been disclosed andare pointed out in the annexed claims, it will be understood thatvarious omissions, substitutions and changes may be made by thoseskilled in the art without departing from the spirit of the invention.

What is claimed is:

1. The method of making coated sheet materials having waterproof andgreaseproof characteristics whichincludes, providing a base sheet,preparing a. coating compound by mixing latex, an aqueous solution ofanimal glue, a tanning i agent and an alcohol, spraying a layer of theteristics which includes, providing a base sheet,

preparing a coating compound by mixing latex, an aqueous solution ofanimal glue, a tanning agent and an alcohol, projecting said coatingcompound over a surface of said base sheet, wiping the coated surfalceof the moving sheet into contact with a relatively rigid and stationarybroad-edged element whereby to spread said compound uniformly over saidbase sheet and compress the compound into the surface fibres of the basesheet to provide an impervious coating, and removing the liquid fugitivecomponents from the body under treatment.

3. The method of making coated sheet materials having Waterproof andgreaseproof characteristics which includes, providing a base sheet,preparing a coating compound by mixing latex, an aqueous solution ofanimal glue, a tanning agent and an alcohol, projecting said coatingcompound over the surface of said sheet as it moves along in a linealdirection, wiping the coated surface into contact with a relatively4rigid and stationary broad-edged element whereby to spread said compounduniformly over said base sheet as it moves along in a lineal directionand simultaneously compress the compound into the surface fibres of thebase sheet to provide lan impervious coating, and removing the liquidfugitive components from the body under treatment.

4. The continuous method of making coated sheet materials havingwaterproof characteristics which includes, providing a continuous web ofthe base material, preparing a coating compound by mixing together from40% to 60% of latex, 30% to 50% of liquid animal glue, a tanning agent,and an alcohol, applying said coating compound to the surface of saidweb during its lineal travel, wiping the coated surface of said movingweb into contact with a relatively stationary broad-edged elementwhereby to spread said compound uniformly over and impress said compoundinto the surface fibres of said web during its lineal travel, andremoving the liquid fugitive components from the body under treatment.

5. The continuous method of making coated sheet materials havingwaterproof characteristics which includes, providing a roll ofcontinuous webbing of the ibase material, preparing a coating compoundby mixing together from 40% to 60% of latex, 30% to 50% of liquid animalglue, a tanning agent, and an alcohol, projecting said coating compoundover the surface of said webbing during its lineal travel, wiping thesheet to provide an impervious coating, removcoated surface into contactwith a relatively rigid ing the liquid fugitive components from the bodyand stationary broad-edged element whereby to under treatment, andplacing said coated webspread said compound uniformly over said webbingin a roll.

bing duringits lineal travel and compress the 5 HORACE A, SHEESLEY,compound into the surface bres of the base

